Suction dredger installation, more particularly a towed dredger



1968 J. M. DONKERS SUCTION DREDGER INSTALLATION, MORE PARTICULARLY A TOWED DREDGER a- Sheets-Sheet i Flled June 21, 1965 INVENTOR vmcmaus M. oouxsas -BY y' 'nvv ATTORNEYS Oct. 29, 1968 J. M. DONKERS 3,407,520

SUCTION DREDGER INSTALLATION, MORE PARTICULARLY A TOWED DREDGER Filed June 21, 1965 S Sheets$heet 2 /Y/ /////VV INVENTOR N D0 NKE R S 1 ATTORNEYS JACOBUS Oct. 29, 1968 J M. DONKERS 3,407,520

SUCTION DREZDGER INSTALLATION, MORE PARTICULARLY A TOWED DREDGER Flled June 21, 1965 3 Sheets-Sheet 3 INVENTOR JAcoBUs M. DONKERS ATTORNEYS United States Patent 3,407,520 SUCTION DREDGER INSTALLATION, MORE PARTICULARLY A TOWED DREDGER Jacobus Marinus Donkers, Amsterdam, Netherlands, assignor to Verschure & Co.s, Scheepsweri en Machinefabriek N.V., Amsterdam, Netherlands, a Dutch Manufacturing company Filed June 21, 1965, Ser. No. 465,280 Claims priority, application Netherlands, Sept. 3, 1964, 6410256 2 Claims. (Cl. 37-58) ABSTRACT OF THE DISCLOSURE A suction dredging assembly of U-shaped configuration pivotally connected to and straddling a vessel and carrying a sand pump to be swung into and out of the water between operative and inoperative positions. The pump has a suction opening and one arm of the U-shaped assembly provides a guide receiving one end of a suction line movable into registry and communication with the pump suction opening.

The invention relates to a suction dredger installation.

A suction dredger installation of this kind is known wherein a member together with the pump is displaceable vertically along guides provided on the vessel, the displacement being effected in a box or at the side edge of the vessel. The invention provides an improved suction dredger installation of this type, wherein the said member is substantially U-shaped and the two top ends of the U are pivotally connected on either side to the bow or stem of the vessel, the sand pump is secured to the member at the bottom of the U and when the U-shaped memher is in the raised and lowered positions respectively the sand pump is respectively above and beneath the water and the member respectively engages around the bow or stern of the vessel and extends downwards. This improved suction dredger installation comprises a vessel without a box for the suction pipe, and which is of simple construction like any other ship but which is also readily manoeuvreable because the member and the sand pump are not on the side edge of the vessel but are at the bow or stem. The construction is such that the member and sand pump do not or at least substantially do not project beyond the width of the vessel because said parts are situated at that part of the vessel which is of reduced width. Of course the maximum width of a vessel determines the width of the waterways, bridges or sluices that the suction dredger installation can pass. Another advantage of the suction dredger installation according to the invention is the considerable stiffness of the U- shaped member. The stiffness governs the length of the member and hence the maximum depth of submersion of the sand pump and hence the depth at which sand can be dredged.

The great stillness of the U-shaped member is obtained by the use of very little material, so that the resistance of the downwardly directed member to travel is reduced. The resistance of the installation to travel is also very small because of the absence of vertical skin guides for the member and the absence of any box. This applies particularly to the installation according to the invention when the member is in the raised position. The force as a result of inevitable resistance to travel exerted on the submerged member and pump by the water is taken simply by the member hoisting ropes, which can also be used as stay ropes. The latter stiffen the member in the direction of travel. Another important advantage is the excellent accessibility of the sand pump when the member is in the raised position. At least one of the 3,407,520 Patented Oct. 29, 1968 two arms of the U preferably contains a guide for a suction bend, and when the U-shaped member is in the lowered position this guide a'djoins a guide for the same bend on the deck of the vessel.

The suction dredger installation according to the invention can readily be made symmetrical, for example by the use of two sand pumps and two suction pipes. This is very important to the manoeuvreability of the vessel, particularly a towed vessel.

The invention will be explained with reference to the drawing, wherein FIGS. 1, 2 and 3 are respectively a top plan, side and front view of a suction dredger installation according to the invention.

The suction dredger installation illustrated consists essentially of a vessel 1, a U-shaped member 2 connected to the bow of the vessel so as to be pivotable about the axis 3 extending above the water, such connection being made at the top ends of the U, and two sand pumps 4 which are secured to the bottom of the U and which are each connected to a suction pipe 5 and a delivery pipe 6.

The bearer can assume two positions inter alia, name- 1y, a raised position in which the suction dredger installation is inoperative, in which case the member 2 extends horizontally, and engages around the bow of the vessel 1, and the sand pumps 4 are situated above the water line so as to be readily accessible for maintenance and repair; and a lowered or operative position in which the member 2 extends downwards and the sand pumps 4 are submerged. Two brackets 7 are mounted at the forepart of the vessel 1 and have pulleys 8 for hoisting and staying ropes 9 which are wound on a winch and which are secured to the underside of the member 2. Each side edge of the member 2 has a guide 10 for a shoe 11 of a suction bend 12. In the operative position, the bend 12 forming the top end of the suction pipe 5 is situated opposite the suction aperture 13 of the sand pump. A bracket 14 with a pulley 15 and a fixed guide for the shoe 11 are provided for the suction bends on each side of the vessel on the deck and above the axis 3. In the vertical position of the member 2, the guide 16 adjoins the guide 10. By means of a lifting cable 17, which extends over the pulley 15 from a winch, the suction bend 12 can be raised from the operative position in register with the suction aperture 13, as far as the deck and be returned to the operative position.

Brackets 18 with the necessary winches, pulley and ropes are provided for lifting and paying-out the middle and suction head of each suction pipe 5. These brackets 18 are adapted to swing down about the horizontal axes 19 in such a manner that in the operative position they project beyond the side of the vessel while when the suction pipes 5 are hauled inboard they can be swung inwards together with the pipes 5 from the operative position so that the pipes 5 can rest on deck. This suction dredger installation according to the invention is very suitable as a towed dredger because the resistance to travel is low and if two pumps and two suction pipes are used each can be arranged symmetrically on one side of the vessel so as to be readily operable. The pipe for the delivery line 6 on the member 2 is connected to the fixed pipe thereof by means of a coaxially pivoting coupling, so that the pipe on the said member 2 is also coaxially pivotable. The suction bend 12 is also mounted in the guide shoe 11 so as to be coaxially pivota'ble with respect to the suction aperture 13.

What I claim is: t

1. A suction dredger installation, more particularly a towed dredger, consisting essentialy of a vessel, a sub stantially U-shaped member presenting arms joined at one end and pivotally connected at their other ends to the vessel on either side thereof, at least one sand pump secured to themem'ber at said one end thereof so as to be submerged and raised from the water, suction and delivery lines connected to the pump, means for swinging said member about the axis of its pivotal connection to the vessel so that when the U-shaped member is in raised and lowered positions respectively the sand pump is respectively above and beneath the water and the member respectively engages around the 'bow or stem of the vessel and extends downwards, at least one of said arms containing a guide, said suction line including a suction bend received in said guide, a fixed guide secured to the vessel in a position to be in register with the first mentioned guide when said U-shaped member is in lowered position, and means for moving said suction bend within said guides.

2. A suction dredger installation, more particularly a towed dredger, consisting essentially of a vessel, a substantially U-shaped member presenting arms joined at one end and pivotally connected at their other ends to the vessel on either side thereof, at least one sand pump secured to the member at said one end thereof so as to be submerged and raised from the water, suction and delivery lines connected to the pump, means for swinging said member about the axis of its pivotal connection to the vessel so that when the U-shaped member is in raised and lowered positions respectively the sand pump is respectively above and beneath the water and the member respectively engages around the bow or stem of the vessel and etxends downwards, and a guide extending along one arm of said member, said sand pump having a suction opening at the lower end of said guide, said suction line having an end portion movable within said guide to a position aligned and in communication with said suction opening.

References Cited UNITED STATES PATENTS 939,227 11/1909 Diehl 3764 80,225 7/1868 Robertson 37-61 143,269 9/1873 BaZin 3763 1,712,312 5/1929 Sensibar 37 72 2,651,122 9/1953 Brinkman 37 5s XR FOREIGN PATENTS 31,052 10/1933 Netherlands.

ABRAHAM G. STONE, Primary Examiner.

A. E. KOPECKL Assistant Examiner. 

